AML team · layered ownership exposure
CH × sanctions cross-link
The problem
Sanctioned individuals don't usually appear as direct counterparties; they appear as PSC owners of layered corporate structures. A KYB workflow that screens the corporate name alone misses the exposure. LSAG-2025 explicitly wants the screening to walk to UBO level and flag any sanctioned individual at >=25% effective stake.
How Stratum fits
The CH-watch + sanctions-screening composition runs the PSC walk to depth 5, computes UBOs at >=25% effective stake (lower-bound aggregation through chains), then runs sanctions + PEP + adverse-media against each UBO + the corporate name. The result carries an explicit per-UBO `sanctionsHits` rollup. Pair with the suite-letting-agent or suite-conveyancer endpoints for one-PDF delivery.
One request
# Request
curl https://api.stratumapis.com/v1/ch/companies/00445790/psc-tree?screen=true -H "x-stratum-key: $KEY"
# Response
{ "companyName": "Acme Holdings", "ubos": [{"name": "Alice Smith", "effectiveStake": 0.56, "uboScreening": {"sanctionsHits": 0, "pepMaxTier": "MEDIUM"}}], "unresolved": false }Set $KEY from your dashboard.
Frequently asked
How do you compute effective stake through chains?
Lower-bound aggregation: 75% × 75% = 56.25%. Control-natures (right-to-appoint-and-remove-directors etc) qualify regardless of share %. Mirrors MLR-2017 reg 5(1)(a) + 5(1)(c).
What if the chain has a non-UK parent?
The walker stops at the non-UK leaf with a flag; the response surfaces unresolved-walk = true so the caller can flag for manual review or supplement with the foreign-registry data.
Is this LSAG-2025 compliant?
Yes. LSAG-2025 §B sets the >=25% UBO threshold + the sanctions/PEP/adverse-media expectation; the response shape covers all three. Pair with the audit-cert PDF for hash-verifiable retention.